Internal peening apparatus



Dec. 23, 1969 H. w. BURNEY INTERNAL PEENING APPARATUS 4 SheetsSheet 1Filed May 10, 1966 INVENTOIR Hlfidl \M Bl/EWE) ,(M ATTORN g Dec. 23,1969 H. w. BURNEY INTERNAL PEENING APPARATUS 4 Sheets-Sheet 2 Filed May10, 1966 INVENTOR M4201 0 W. BMQ/VEY RE--- q Ff au 2 I l I 1 1 i 1 l IvM ATTORNEYJ 4 Sheets-Sheet 5 Filed May 10. 1966 INVENTOR HAQDLD EMF/Vi)BY ,CQM fa W ATTORN X5 Dec. 23, 1969 H. w. BURNEY 3,435,073

INTERNAL PEENING' APPARATUS INVENTOR M12040 w. awn/my ATTORNEYJ UnitedStates Patent 3,485,073 INTERNAL PEENIN G APPARATUS Harold W. Burney,Hackensack, NJ., assignor to Metal Improvement Company, Carlstadt,N..l., a corporation of New Jersey Filed May 10, 1966, Ser. No. 548,976

Int. Cl. B24c 3/16 U.S. CI. 7253 12 Claims ABSTRACT OF THE DISCLOSUREThis invention relates to peening apparatus. It is particularly adaptedfor peening the internal surfaces of various components where access isvery difficult, but Where it is important to strengthen the internalsurfaces. The peeningeffeet of shot impacting the treated surface atrelatively high velocity gives an effect similar to cold working of themetal.

It has been extremely ditficult in the past to provide a convenient andlogical procedure for reaching internally of small tubular, cylindricalor hollow elements, because of the difficulties of space limitations inthe type of article worked upon, and the necessity of accuratelycontrolling both the volume or density of the shot used, as well as thevelocity at which the shot strikes the surface to be worked. Furtherthan this, because of the non-planar character of the impacted surfaceto be worked upon, it has, in the past, been ditficult to obtainadequate uniformity of working over the entire range, particularly wherethe ejected shot often travels over substantially different path lengthsprior to the actual impact. Further, in the past, such surfaces wereoften peened by rotating the work about the peening nozzle. Thisoperation often required excessive working space and became completelyuneconomical, particularly where only a small portion of a large articlerequired peening.

The apparatus here to be described and claimed will set forthparticularly its use for peening the internal surfaces of tubularelements or hollow generally cylindrical elements, such as cylinders,tubing, connectors, ducts, pipes or the like. In its preferred form, thepeening apparatus here to be described embodies a tubular lance elementhaving a peening head or nozzle attached at one end there of. Thepeening head and the end of the lance to which it is attached arepositioned internally of the surface region which is to be worked upon.The work is preferably carried upon and clamped to a support surface orplate within which numerous openings are provided and about one largeopening of which the Work is generally centered, with the lance beingadapted to be moved in both a rotary and a reciprocating path throughthis large opening. The lance may be supported relative to thework-support plate so that when it protrudes through the large openingtherein, it will be held in a substantially fixed relationship laterallyrelative to the work. The lance, with the peening nozzle securedthereto, is rotated internally of the work at a selected rotational spedand simultaneously reciprocated through a selected number of cycles orstrokes per unit time period. The rotation and reciprocation is achievedby supporting the end portion of the lance remote from the nozzle from aplatform, a suitable drive mechanism for providing rotation, as desired,being included. Normally, the lance is capable of being rotated ineither a clockwise or a counterclockwise direction, as conditionsdemand. This is because in many peening operations it is often desirablethat the peening nozzle and the lance shall each make some selectednumber of rotations Within a selected time period following which thedirection of drive and rotation may be changed, with the peening headand the lance turned in the opposite direction.

The support platform is motor driven and mounted upon or within astandard for slidable up and down reciprocation concurrently with lancerotation. Suitable limit controls of the up and down reciprocatorymotion are provided so that the length of the reciprocating stroke maybe selectively controlled.

In some forms of the apparatus, the lance-drive motor may be supporteddirectly upon the platform which is reciprocated. The motor shaft may behollow, where desired, so that the tubular lance may be fitted tightlytherein. In this connection the peening shot and fluid are passeddirectly through the motor shaft from one side of the motor shaft fromone side of the motor to the other. Alternatively, the motor shaft, ifhollow, may connect to the tubular lance on one side and on the otherside, may conmeet to a flexible feed connection by way of a swivelhearing. The feed connection is adapted to supply peening shot and fluid(such as air under a selected pressure) through the unit therebyeventually to discharge the shot and fluid outwardly through the nozzleto impact the work.

The apparatus usually comprises also a suitable means for gathering theshot ejected from the nozzle at a time subsequent to its ejection andimpact upon the work to be treated. The used shot is thereby recoveredand returned through a suitable cleaning component for recirculation.Following this plan, the cleaned shot is discharged to be mixed with theapplied fluid, such as air, through a suitable mixing valve in order tobe reused.

Normally, the connection from the mixing valve to the lower end of thelance is by way of a flexible cable so that the drive and reciprocatingunits for turning and reciprocating the. lance 'may be driven freely inany desired fashion. The swivel bearing connection already describedbetween the flexible supply element and the end of the lance permits thelance to rotate freely relative to the supply connection irrespective ofthe. precise rate of rotation. Various modifications, of course, may bemade within the spirit of what is herein described without departingfrom the spirit and scope of what is considered new and novel and whichis defined by the claims later appended.

The invention has been illustrated in one of its preferred forms by theaccompanying drawings wherein:

FIG 1 is a top plan view of one preferred form of the invention;

FIG. 2 is a side elevational view taken approximately on the line 2-2 ofFIG. 1 looking in the direction of the arrows;

FIG. 3 is a front elevational view looking at FIG. 1 approximately onthe line 33 with the side closuredoor In Open position;

FIG. 4 is an isometric view showing particularly the drive and lancemovement;

FIG. 5 is an elevational view to show the work holder means secured tothe top closure member through which the rotary and reciprocating lanceis moved; and

FIG. 6 is a view in section showing the peening nozzle tip and theconnection of the lance tube thereto.

Referring now to the drawings, and considering first the combination ofFIGS. 1, 2 and 3, the lance tube 11 is positioned generally centrally ofa framework comprising pairs of side upright members 12 and 13 whichconnect to each other by a series of cross members 14, 15, 16 and 17.The upright side members and cross members form collectively an openframe member within which the lance is supported. A platform 20 is shownapproximately in a mid-position along the upright frame. It is held byside members 21 and 22 for movement up and down along a pair ofvertically positioned angle brackets 23 and 24.

The platform 20 is secured to a pair of bracket members 27 and 28 bysuitably secured cross-members 25. Roller members 29, 30, 31 and 32 formend support elements adapted to rest and roll on the guide elements 27,thereby to move the platform, as a whole, up and down. A bracket 37extends outwardly from the corner upright support 13 and is apertured toprovide one guide or bearing point( not shown) for the control rod 38.The control rod extends upwardly adjacent to the side of the frame. Atits upper end 39, the rod is secured by a suitable link attachment to aswitch element 40 adapted to connect into a switching unit 41.

A second bracket 43 extends outwardly from the platform 20 and has anaperture at its outer end through which the limit switch rod 38 ispassed. Collars 45 and 46 are secured about the limit switch rod 38 andspaced apart appropriate to establish, as will later become apparent,the stroke length of reciprocation of the lance member 11 which iscarried from the platform.

The platform 20 is adapted to be held to and moved up and down by theconnection thereto of suitable drive cables or V-belts 51 and 52. Thedrive cables attach to one end to the platform and then pass downwardlyand around idler pulleys 53 and 54 which are carried by an idler shaft55 whose ends are suitably supported in bearings 57 at opposite frameupright members. The drive cable 52 also wraps over a pair of drivepulleys 58 and 59 held on a shaft 60 carried in the upper portion of theframe. The shaft 60, on one side, protrudes outwardly from the frame anda pulley 63 is secured thereto for driving purposes through a cable 64.The cable also wraps about a pulley 65 secured at the end of the shaft66 to the motor mount and assembly schematically represented at 67. Themotor 67 drives into a gear box assembly 68 which-determines thespeed ofrotation of the driving shaft 66 for the drive pulley 65.

The motor 67 is capable of being driven either forward or backward. Forthis purpose, the already mentioned switch element 40 and switch box 41provide a control (not shown in the drawings). The cable 64 drives thepulley 63 attached to shaft 160 at a speed proportional to therotational speed of the drive pulley 65. This, in turn, with the shaft60 being secured in bearings 69 on the. frame, establishes an up anddown drive for the platform'20.

Reversal of the platform isestablished through the reversal of positionof the switch 40 of the switch box 41, as determined by the'position ofthe collars 45 and 46 on the'rod 38 which are contacted by slider 72which is secured to the V-belt 51. Cushioning of the movement of thelimit switch rod 38 is provided by spring members 70 and 71 Whoseposition is established by the locating collar 46 and a second collar73. So arranged, the platform 20 and the motor 91 carried thereby forturning the lance element 11 is adapted to be moved up and down in areciprocating path of selectively fixed stroke lengths, the path lengthbeing determined, as above noted, by the spacing between the collars 45and 46 to bring about a reversal of drive of the belts '51 and 52, asdescribed.

At the same time that the assembly is being moved up and down, the motor91 is permitted to rotate thereby to drive the lance in either aclockwise or counterclockwise direction determined by the direction ofmotor rotation. The motor 91 is preferably of the worm-geared type todrive the lance at any desired rate. For one satisfac tory operationthis was at 86 r.p.m., although this valve is purely illustrative andnot limiting. Peeningshot moved.v

forward under the influence of a supplied fluid pressure (such ascompressed air) are supplied by way of the flexible hose-like connection97 which connects with an extension 98 of the motor shaft through theswivel joint 99. The lance 11 may extend directly through the hollowrotor shaft (not shown) of the motor 91 or the interior of the hollowrotor shaft may be formed of hardened material so that the shaft itselfforms a passageway for peening shot and fluid to passtherethrough to thelance 11. In either instance, a swivel connection, such as 99, isdesirable to preclude all possibility of the connection twisting andaccidental shut-off. At the same time the The peening shot which aresupplied through the nection 97, are made available from a supply 101fed down through a valve 102 of any desired character t'o 'be' swivelprovides an easy connection .of a very satisfactory mixed in the mixingchamber 103 into whichtfluid under pressure is also supplied by way ofthe indicated connection 104. Depending upon the pressure adopted andthe opening within the valve 102, the amount of peening shot fedoutwardly from the supply 101 maybe determined.

It is often desirable in a peening operation of the character here setforth that the lance tube andkthe nozzles carried thereby shall make afixed'number of revolutions in one direction during the course ofmovement up and down along the reciprocating path taken bythe lance rod11. A counting mechanism, conventionally shown at 105, provides'thisindex. It also provides that after a count of some selected number,current will be fed into the 1 counting mechanism to provide a reversalof current into the drive motor thereby to reverse it. Normally,controls may also be applied directly electrically by means of a panelbox 106 having a series of buttons for the on and off control, as wellas the forward and reverse in known fashion.

So far, in this description, only indirect mentionhas been made of thepeening mechanism per se. The particular peening nozzle is shown in moredetail by FIG. 6.

This component in its preferred, form is essentially cylindrical inshape and has its ejection portion or throat 108 shaped to follow anoptimum shot ejection path. The

nozzle per se is formed of extremely hard metal, usually a tungstencarbide composition. The nozzle is attached at the upper end of thelance in approximately the location indicated by FIG. 5 and shownfurther by FIG. 4. The diameter of this nozzle, considering the factthat the unit is particularly adapted for use on internal cylindricalsurfaces, is just slightly greater than thatof the lance tube so thatwhen shot are forced upwardly through the lance tube 11 under theinfluence of pressure applied from a source (not shown), the shotwhichare within the lance tube 11 will be ejected first upwardly and then,upon striking the curved portion 109 of the internal wall of the nozzle,will be redirected along a-path (usually substantially at a right angle)which is angular relative to the axis of the lance element. .'With thisoccurring, shot moving upwardly through the lance tube 11- reach thenozzle 107with reasonably high velocity and are forced outwardly fromthe nozzle opening 111 in well known fashion.

It is important that the internal diameter of the lance tube be justslightly greater than the internal diameter of.

the base of the nozzle in order that the' shot ejected from the lanceand into the nozzle shall have a generally free path of movement exceptas that movement is charged by the nozzle shaping.

With the typeof work adapted to peening, shown as, theinternalsurface115 of an assumed generally -cylin- A drical or tubular inner surfacecharacteristics (see FIGS.

5 and 6) the work is held securely to the topmember 118 and arrangedgenerally to surround an enlarged opening 119 in the top plate throughwhich the lance pro trudes.

As can be seen particularly from FIG. 5, the diameter of the opening 119is substantially greater thanthat of the lance although, of course, lessthan the interior of the work piece 115 to be handled. For theseConditions obtaining, shot ejected from the upper end of the lance tubeinto the nozzle first strike the interior of the work piece. There, thesurfacetoughening occurs. The projected steel balls after impact on thesurface to be treated then drop gravitationally onto the upper surfaceof the top member 118. l

Some of the shot, after having been ejected to impact the internalsurface of thew'ork piece 115, return to the supply hopper or bin 101 byfalling through the openings 120 in the top member 118. However, someshot, if quite small, may fall through the opening 119, provided thisopening is sufficiently larger than the lance which extendstherethrough. In the supply hopper, the used shot are cleaned prior torecirculation. The return to the supply hopper is schematicallyindicated by the gravitational drop provided by way of the path 123. l I

Various ways and means may be provided for holding the work to the topmember 118 for action by the peening jet. One form of work-holder hasbeen schematically represented particularly in FIGS. 1, 3 and 5 wherethe work 115 is rested upon and held to the top plate. Clamping members125 and 126 are rested upon the top plate 118 to extend outwardly fromeach side of the work. The clamp members have foot sections 127, 128which are slotted (as indicated) and adapted to receive suitablefastening bolts 129. The upright sections of the clamping elements 125,126 extend upwardly from the support and bend in a substantiallyL-shaped pattern to turn inwardly at 130 and 131. Each inwardly turnedsection has an internal edge which is adapted to fit over and clamp tothe work. These inwardly turned sections 130, 131 have laterally andoutwardly extending arms 132, 133 which are adapted to be boltedtogether by suitable fastening bolts 135, 136 (see particularly FIGS. 1and 5).

With the work 115 being placed within the holder to rest upon the upperplate 118, and the holder also held thereto in loosened position by thebolts 129, the support members are then moved inwardly along the slottedportions 127 or 128. Then, with the inwardly turned sections 130 or 131brought into engagement with the work, the bolts 129 are suitablytightened thereby to hold the support member fixedly to the upper plate.At this time, the bolts 135 and 136 are also tightened thereby to holdthe upper section of the work tightly to the clamp.

At times, it is desirable to provide an additional tightening elementadjacent to the work and to fit between the work and the support on thetop member 118. This is provided by a suitable shim or wedge-likestructure conventionally represented at 137. This shim may be rigid orresilient. Its main function is to fill the space between the supportand the work. The foregoing is merely illustrative of various ways andmeans that may be adopted to hold the work but the above describedcomponent is easily used and equally reusable thereby adequate for timesaving in introducing new component parts.

The entire assembly may be housed or closed in by closure doors, asdesired. One such closure door is represented particularly by the door141 (see FIG. 1 for closed position) which is adapted to turn abouthinges 142 on a support rod 143 thereby to move from the closed positionof FIG. 1 to the open position of FIG. 3. The other sides of the casinglikewise may be enclosed as desired. Further, by reason of the peeningaction, it is often desirable also to close off the upper section of thecasing wherein the work is supported as indicated by FIG. 5.

Various other and further modifications may be made as will appearevident from what has been disclosed and as may be fully Within thescope and spirit of the claims hereafter appended.

Having now described the invention what is claimed is:

p 1. Peening apparatus for peening the interior surfaces of a workpiece,said apparatus comprising platform means for supporting the workpiece,said platform means having an opening so located as to be substantiallycentrally positioned relative to the interior of the workpiece supportedthereby,

- a tubular lance member,

'means for supporting the lance member in substantially cantileverfashion so that the lance extends substantially along an axial pathrelative to the workpiece interior and is projectable interiorly of theworkpiece along the axial path through the platform opening so as tomake it movable to controllable positions interiorly of the workpiece,

a nozzle element having its inlet secured to the end of the lance memberwhich is movable within the workpiece through said opening and havingits outlet directed substantially normal to each of the axial paths ofthe lance member movement and to the interior of the workpiece supportedby the platform,

motor means carried upon the lance support member and connected forrotationally driving the lance member and for providing substantiallycontinuous power thereto, thereby to establish its rotation relative toa supported workpiece and to turn the secured nozzle at the free end ofthe cantilever lance member with lance member rotation,

motor means for also controlling the reciprocatory movement of all ofthe lance support means, the motor support, the lance and the nozzlemovement along the axial path and the stroke length of movement of thelance and nozzle within the workpiece through the platform opening, and

means to supply peening shot under fluid pressure within the lancemember for discharge through the nozzle during rotation andreciprocation, thereby to peen the workpiece interior.

2. The apparatus claimed in claim 1 wherein the work support for theworkpiece is apertured to an extent more than that required for themovement of the tubular lance member therethrough to permit the returnof shot ejected from the nozzle for reuse.

3. The apparatus as claimed in claim 1 comprising, in addition, meansfor controlling the reciprocatory movement of the lance support withinadjustable limits.

4. The apparatus as claimed in claim 3 comprising, in addition, means toreverse the direction of drive of the motor at the end of eachreciprocatory path of movement of its support means.

5. The apparatus claimed in claim 1 comprising, in addition, a flexiblemeans and swivel joint means connected to the supported end of thecantilever lance member to supply peening shot and fluid under pressuretherethrough for final ejection through the nozzle.

6. The apparatus as claimed in claim 2 comprising, in addition, shotgathering means positioned beneath the work support platform and itsapertured region for gathering used shot for reuse subsequent to theshot ejection from the nozzle toward the supported workpiece.

7. The apparatus as claimed in claim 5 comprising, in addition, arotatable coupling connection between the flexible supply means forpeening shot and fluid under pressure to the supported end of thecantilever type lance element.

8. The apparatus as claimed in claim 1 wherein the lance rotating motormeans is provided with a hollow shaft member and wherein the supportedend of the lance member extends through the hollow motor shaft formaking its connection with the flexible supply means.

9. The apparatus as claimed in claim 8 comprising, in addition, aplurality of upright frame members,

means associated with the lance support member and addition,

a slidable platform carried for up and'down movement within theframework for guiding the same,

means carried by the platform for rotationally moving the lance member,

means carried by the platform for guiding the said platform in its upand down movement along the guide means, and

means for determining the length of reciprocating stroke of the lancemovement.

11. The apparatus claimed in claim 10 comprising, in

addition, a supply container,

means for supplying used shot to the container, and means for feedingcleaned used shot to the lance member.

12. The peening apparatus claimed in claim 1 wherein 1 8 the peening.nozzle carried on the free end of the cantilever lance member comprisesa communicating passage between the entrance and exit. ports having acurvature covering an arc of the order of the said curvature varyingfrom a nominal curvature at the point of connection of V the nozzle tothe. free end of the lance member and progressively increasing incurvature in the direction toward theexit port whereby peening shotforced through the lance member have minimal velocity reduction in thecurved area of the nozzle and are projected outwardly from the nozzle ina direction substantially 90 from the lance axis.

References Cited UNITED STATES PATENTS RICHARD J. HERBST, PrimaryExaminer

